Most electronic circuits include one or more switching mechanisms to selectively route electrical signals to different components in the circuit. Such switching mechanisms are most often solid state, transistor-based switches, electro-mechanical devices, such as relays, or purely mechanical switches that are moved by hand. While such switches work well for relatively low frequency signals, more sophisticated mechanisms are required as the frequency of the electrical signals to be switched extends into the Gigahertz range.
When switching high frequency signals such as microwave signals, the switch must be carefully designed to avoid any unnecessary reflections of the signals and losses in the signal path. For example, commonly used microwave switches typically have a number of solenoid driven contact pads that are mounted on the ends of plastic rods. The contact pads are selectively lifted from, or placed onto, a circuit board in order to break or make an electrical connection. Each contact pad is a precision made machined part that springs when it is flexed so that the contact pad is somewhat self-cleaning. The precision with which the parts of such a switch design must be made makes this type of switch design very expensive to manufacture. Furthermore, it is very difficult to balance the cleaning action of the contact (through micro-machining, hand adjustments or lubricants) against contact wear. Long life of the contact (more than ten million operations) or guaranteed first time operation are hard to achieve and are often not met. Finally, such switches can have relatively low isolation due to the capacitive connection created when the contact is lifted a short distance from the circuit board.
Given these problems and others, there is a need for an improved electrical switching system that can be used with microwave or other signals.